Re: [boost] [thread] RFC standard proposed mutex, read-write mutex, condition

From: Yuval Ronen (ronen_yuval_at_[hidden])
Date: 2007-08-25 16:39:15

Howard Hinnant wrote:
> On Aug 25, 2007, at 2:52 PM, Yuval Ronen wrote:
> 
>> I find the lock argument cumbersome. In a way it's redundant to  
>> passing
>> the mutex, and for no good reason - just for hinting, subtle or no
>> subtle. Where else in C++ a user is hinted in such a way? It's without
>> precedent, and plain weird in my eyes. And if we add to this the fact
>> that it's only a partial compile-time check, then it makes things even
>> weirder. The user, for example, can confuse and think that he is fully
>> covered by the compile-time check, and continue with his guards down,
>> passing it a non-owning unique_lock. If we can't do a complete job,  
>> it's
>> better to not do it at all, at least this way our users are forced  
>> to be
>> aware of what's happening.
> 
> We have to have a wait which takes at the very least a mutex, if not a  
> lock.  This is to support the legal "dynamic" binding mutex binding.   
> We could possibly achieve the same functionality through your  
> set_mutex suggestion, but that interface seems error prone to me, as  
> it then takes two calls to wait instead of one:

More "error prone" is in the eyes of the beholder, I guess...

> One possibility would be to have both wait(lock) and set_mutex(mutex)/ 
> wait().  But this doesn't allow anything that wait(lock) alone allows.

I'm not advocating those overloads, not at all.